you're describing the exact chicken and egg problem that we need to take the first steps on with "people still need a car in Seattle". That's only true because Seattle forced buildings and roads to be car oriented for decades, reforms like this are meant to reverse that because the environmental costs are catastrophic.

People don't necessarily need cars in NYC, Chicago, DC, SF, etc because a majority of the housing in those places was built before car oriented zoning became the norm in basically every major city. We have to start rolling that back, it's insane policy.